Rubio has had plenty of company in the GOP in making a new round of attacks on President Barack Obama’s signature policy.

Here’s a look at five of Rubio’s attacks on Obamacare.

1. "The American people support defunding Obamacare and oppose shutting down the government." Mostly False.

Sept. 20, 2013 in a press release.

Rubio makes it sound like he has support from the public for his main objective, which is defunding Obamacare. He doesn’t. When asking the public about Obamacare, word choice matters, and "defund" leads to a different result than "repeal." While the law isn’t popular, a recent Kaiser poll found 57 percent opposed cutting off funding. On his second point, he’s right that most people tell pollsters they don’t want a government shutdown. But we’ll point out that both sides in the budget battle in Congress say they don’t want a shutdown. We rated his statement Mostly False.

2. Under Obamacare, people who "have a doctor they’ve been seeing for the last 15 or 20 years, they won’t be able to keep going to that doctor." Mostly False.

July 31, 2013 in a Fox News interview

Some have suggested that Obamacare would interfere with doctor-patient relationships. Actually, there’s no more interference than what existed before Obamacare. Right now, patients can lose access to their doctors when their insurance policies change. This typically happens when employers switch plans or when workers switch (or lose) jobs. Under Obamacare, some patients who buy health insurance through the marketplace could lose access to their current doctor, but it’s difficult to predict how many. And it would be because they have a new insurance plan. We rated that claim Mostly False.

3. "Even the employees’ union for the IRS -- the very people in charge of enforcing this law -- are begging to be let out from under this law." Mostly False.

July 31, 2013 in a Fox News interview

The National Treasury Employees Union has asked its members to oppose efforts to force its members into the exchanges created by Obama’s health care law. But Rubio ignored a lot of context that would give a listener a different impression. The union’s quarrel is not with Obamacare itself, but rather with efforts by the law’s opponents to uproot federal employees from their longstanding health plans, a change the union views as punitive. By contrast, Obamacare was written to keep as many Americans as possible on their existing insurance plans, with the exchanges envisioned as a way for people without insurance or with inadequate insurance to purchase a plan. We rated the statement Mostly False.

4. Under Obamacare, "75 percent of small businesses now say they are going to be forced to either fire workers or cut their hours." Pants on Fire.

July 25, 2013 in a FoxNews.com op-ed

Suggestions that business are laying off workers because of the health care law have so far proven to be largely unfounded. Most small businesses -- those with fewer than 50 employees -- do not have to provide health insurance to their employees. (In fact, some very small businesses with fewer than 25 employees may qualify for tax credits under the law.) The claim here that 75 percent of small business were reducing their workforce was based on a misreading of a study from the U.S. Chamber of Commerce. The study actually found that less than 10 percent of small businesses said they will be forced to reduce their workforce or cut hours. We rated that claim Pants on Fire.

5. "Obamacare is bad policy that adds around $800 billion of taxes on the American people. It does not discriminate between rich and poor. It hurts everyone." False.

July 8, 2012, in an Orlando Sentinel op-ed

Rubio cherry-picks the highest number he can find — $800 billion in new taxes — to garner opposition to the recently upheld health care law. He doesn’t tell readers that these "taxes" would be garnered over 10 years or take into account that the law includes tax breaks and subsidies for health insurance. The law taxes wealthier Americans to a greater degree to provide more services for the poor. We rated that claim False.